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Vacant Lots / Unpaved Areas

Those areas which do not require a dust control permit or a dust control plan fall under
Maricopa County Air Quality Rule 310.01. The purpose of this rule is to limit the emission of particulate
matter (dust) from open areas, thus protecting the public health.

This section of the rule addresses the use of unauthorized motor vehicles or off-road vehicles which are creating fugitive dust emissions from an
open area or vacant lot. If the area is of sufficient size (0.10 acre) and is being sufficiently disturbed by vehicles (500 square feet disturbed
or more), then the property owner is required to use control measures to limit the emission of dust. The new Maricopa County Ordinances P-27 and
P-28 require that the individual vehicle owner is also responsible to know which property is available for vehicle access. Both the rules and
ordinances work together to close the loopholes in the regulations so we can effectively protect the public health from excess dust emissions.
(see P-27 Vehicle Parking on Vacant Lots and P-28 Off-Road Vehicle Use on Vacant Lots)

Control measures available to property owners include preventing vehicle access by installing barriers or fences. No trespassing signs or postings
are also considered a control measure. Areas that have been disturbed by motor vehicles or off-road vehicles can be restabilized by surface gravel,
chemicals (such as dust suppressants), or organic (such as vegetative cover) means. See Trespass Laws for statutes regarding
illegal trespass on a property.

This section concerns open areas or vacant lots which have a disturbed area larger than 500 square feet (a disturbed area is where the surface earth
has been moved, uncovered, or modified from its native condition). If such areas remain unused and undeveloped for more than 15 days then the owner
and/or operator must use a control measure to help limit the emission of dust from the area.

Control measures for this section includes establishing a vegetative ground cover (such as shrubs and grasses), applying dust suppressants, or applying
surface gravel. The owner/operator could also stabilize and restore all disturbed areas so they are similar to adjacent or nearby undisturbed native conditions.

This section concerns unpaved parking lots where vehicles are parked, maneuvered, or stored. Control measures include: paving; applying dust suppressants; or
applying and maintaining surface gravel. For lots that are used 35 or fewer days per year the control measure is required during the period the lot is
utilized for vehicle parking.

This section applies to any activity directly related to feeding animals, displaying animals, racing animals, exercising animals and/or for any other such
activity, including but not limited to livestock arenas, horse arenas and feed lots. Such activities shall not exceed 20% dust opacity levels. To prevent
the excessive emissions of fugitive dust, the owner and/or operator shall implement one of the following control measures: dust suppressants (water or dust
palliative), surface gravel, or shrubs and/or trees within 50 feet of animal pens, corrals and arenas.

The definition of bulk material is any material such as (but not limited to) earth, rock, sand, mud, construction debris, trash, feeds, or fertilizers that are capable
of producing fugitive dust. If an erosion event causes bulk materials to be deposited onto a paved road or parking lot then the owner/operator of the property which contained
the bulk material shall implement a control measure. Control measures include removing the material from the paved surfaces and disposing of the materials in such a way that
another source of fugitive dust is not created. Control measures have been effectively implemented when fugitive dust emissions do not exceed 20% opacity.

If an owner/operator allows more than 150 vehicles per day to use an easement, right-of-way, or access road, then appropriate control measures shall be implemented.
Control measures include paving, applying dust suppressants (other than water), or applying surface gravel to the disturbed area or install locked gates at the entry points.

Dust Control Methods:

The following general methods of dust control are appropriate, depending upon the circumstance:

Vegetative ground cover. Examples include grass, shrubs, trees, vines, or vegetative debris that is not subject to movement by wind.

Paving the disturbed surface with asphalt, concrete, or other similar material.

Criminal Trespass Laws:

A listing of the Arizona Revised Statutes pertaining to trespassing.
(A.R.S. §§ 13-1502; 13-1503; 13-1504; 13-1603) Note: if trespassers are the source of fugitive dust emissions on a vacant lot or open area, owner/operators
of such an area are required to implement control measures. Owner/operators are then encouraged to notify local law enforcement agencies if the criminal activity continues
to occur.

To report violations:

Use the On-Line Complaint form: click here
or call (602) 372-2703
8:00am - 5:00pm Monday through Friday
(Voice mail is available after business hours)